The dormancy of wild oat seed (Avena fatua L.) from plants grown under various temperature and soil moisture conditions

Abstract

Summary Wild oat plants of types fA, fB and fC were grown at a constant 15 or 20°C during the period of seed maturation. Seed of the three types differed little in dormancy when grown at 15°C, but at 20°C a larger proportion of seeds of type fA were dormant compared with fB or fC. Overall, dormancy of seed produced at 15 and 20°C was 97 and 63% respectively. Plants of another collection of type fB were grown from seed at 15 or 20°C with or without water stress applied only from the time of panicle emergence. Water stress and high temperature reduced viable seed production. Seed dormancy was tested immediately after collection by planting the seed in soil, and by Petri dish tests. Further Petri dish tests were made after 6 months storage. Seedling emergence in the first autumn from seeds of plants matured without water stress at 15°C was 10% compared with 30% for seeds grown at 20°C. Seeds grown with water stress at 15°C gave 47%, and at 20°C 78% emergence. The majority of emergence from seeds formed at 15°C without water stress occurred in the second spring after burial. Petri dish tests support these findings and suggest that seeds produced in hot dry summers are less dormant than those produced in cool moist ones.

Pre- and post-harvest influences on physiological dormancy alleviation of an AustralianAsteraceaespecies:Actinobole uliginosum(A. Gray) H. Eichler

“…This is contrary to results found for members of the Poaceae, including Avena fatua (Peters, 1982), Sorghum halepense (Benech Arnold et al, 1992) and Bromus tectorum (Meyer and Figure 5. This is contrary to results found for members of the Poaceae, including Avena fatua (Peters, 1982), Sorghum halepense (Benech Arnold et al, 1992) and Bromus tectorum (Meyer and Figure 5.…”

“…Invasive weeds within Australia are no exception. It is often observed that maternal drought reduces PD, as seen in the herbaceous weed Sinapis arvensis (Brassicaceae) (Luzuriaga et al, 2005) and Avena fatua (Poaceae) (Peters, 1982). Limited soil moisture during seed development also causes variation in seed dormancy status, depending on the species and the dormancy mechanism(s) involved (Fenner, 1991).…”

Growth and Reproduction of Junglerice (Echinochloa colona) in Response to Water Stress

“…Other grasses, such as annual ryegrass (Lolium rigidum Gaud.) and wild oats, respond similarly (Peters 1982b;Steadman et al 2004). It is possible that similar generalization may apply for junglerice and that the higher temperatures have masked any differences in dormancy brought on by drought stress.…”

The effects of the parent environment on seed germinability

“…This would account for the observation that seeds of stressed Avena fatua plants were found to have four times more (gibberellin-induced) a-amylase than seeds of unstressed plants (Peters, 1982b). This would account for the observation that seeds of stressed Avena fatua plants were found to have four times more (gibberellin-induced) a-amylase than seeds of unstressed plants (Peters, 1982b).…”

“…In Pennisetum typhoides there is very little effect of developmental temperature in the range 22-31 °C, but a marked decline in germinability in seeds developed at 19°C (Mohamed et al, 1985). Its dormancy was first shown to be reduced by higher temperatures during development by Sexsmith (1969), and the effect was confirmed in subsequent studies by Richardson (1979), Sawhney and Naylor (1980), Peters (1982b) and Somody et al (1984). Its dormancy was first shown to be reduced by higher temperatures during development by Sexsmith (1969), and the effect was confirmed in subsequent studies by Richardson (1979), Sawhney and Naylor (1980), Peters (1982b) and Somody et al (1984).…”